Vacuum-tube lamp.



D.MOP. MOORH' VACUUM TUBE LAMP. APPLICATION FILED JAN. 5, 1905.

Patented Dec. 5, 1911.

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. UNITED s'rATEs PATENT OFFICE.

DANIEL llloFAB-LAN MOORE, or NEWARK. NEW JERSEY, AssIoivon ro MOOREELEc- TRICAL COMPANY, OF NEW YORK, N. Y., A. CORPORATION OF REEF YORK.

VACUUM-TUBE LAMP.

To all whom it may concern:

Be it known that I, DANIEL MCFARLAN MOORE, a citizen of the UnitedStates, and a resident of Newark, in the county of Essex and State ofNew Jersey, withpost-oflice address 52 Lawrence street, have inventedcertain new and useful Improvements in Vacuum-Tube Lamps, of which thefollowing is a specification.

My invention relates to devices ordinarily termed vacuum tubes,comprising a sealed inclosure for a gas or vapor through which electricenergy is passed for the. purpose of rendering the contents of the tubeluminous or for other purposes.

The invention relates more particularly to such tubes when operated byalternating currents, and the object is to provide for the operation ofthe same at lower voltages than are permissible when my invention is notemployed.

The invention consists in providing means for heating a portion of theelectrode at each end of the tube by current independent of thedischarge current passed through the same from end to end therebyrendering each electrode more efiicient as a cathode by reducing thediflerence of potential between the same and the gas at those instantsof time when the said electrode is required to operate as a cathode.

My invention consists also in an improved compound electrode one portionof which acts as a cathode and the other as an anode, and also in theimproved combinations of devices now particularly hereinafter describedand then specified in'the claims.

In the accompanying drawings Figure 1 is a vertical section through oneend of a tube embodying an electrode in one of the forms that may beemployed. Fig. 2 shows diagrammatically one wayof connecting the same toa circuit. Fig. '3 is a transverse section through the supporting stemfor the electrode. a

1 is the gas or vapor containing tube through which electric energy ispassed from end to end in the usual manner, one end only of said tubebeing shown. The electrodes at the ends are each constructed preferablywith a central portion 2, which becomes highly heated by the discharge,and which acts mainly. as thecathode at every other alternation or whenthe current is of.

proper direction, and with a surrounding Specification of LettersPatent.

Application flied January 5, 1905. Serial No. 239,727.

Patented Dec. 5, 1911.

portion 3 which is less highly heated during operation and. which actsmainly as an anode. The portion 3 may be made of graphite or otherconductor and the portion 2 comprises preferably a filament of carbonWhose terminals are joined respectively to any suitable source ofheating current adapted to render the same incandescent. portion 3 maybe in the form of a cup or cyllnder suitably joined to a leading in wire4, and the portion 2 has its ends secured respectively to leading inwires 4 and 5 passmg through the glass stem 6 projecting through thebase of the cup 3. Connection between leading in wire 4 and theelectrode 3 is preferably made in the following manner: Stem 6 and thefilament 2, may be the'same as in an ordinary incandescent lamp.Connected to theleading in wire 4 a-t'the inner end of the stem is awire 12, which is carried back and preferably wrapped around the stem 6.Surrounding the stem is a conducting cylinder 13 of carbon or graphiteor other material bisectedlongitudinally on the line 14. The two halvesof the cylinder are boundback upon the stem by means of the binding wire15. Forming a part of the cylinder is a collar or flange 16, upon whichthe perforated base 17 of the electrode 3 is supported. The cylinder. 13is preferably made of graphite, and the Wire 12 and binder 15 arepreferably presses the cylinder 13 against the wire 12,

and forms connection between said cylinder and wire. These parts areassembled upon ,the stem in a suitable manner and then the same isinserted. into the glass tube of the lamp and fused to the base thereofat the point indicated at 18. Afterward the electrode 3 is slipped intothe tube and by resting in contact with the flange 16 is in electricalconnection with the cylinder 13, wire 12, and leading in wire 4. Thealternating current which passes through the tube from end to end may beobtained by conversion, from alternating current mains 8, 8 thesecondary 9 of the converter having its terminals connected respectivelyto the electrodes at the opposite ends of the tube, and being adapted tosupply comparatively high voltage. Heating current for the portion madeof Norway iron which has been treated The 2 of the electrode at each endof the lamp and of suitable amperage but independent of that whichpasses from end to end is obtained from the mains 8, 8' throughconversion by a .converter the secondary of which is indicated at 10,but might be obtained fromv any other source. As will be seen theportion 2 is also connected to the same pole of secondary 9 as portion 3of the electrode. Portion 2 is, therefore, heated not only by thedischarge current circulating in the tube but is also locally heated bythe current from 10. Portion 3 is heated by the discharge current onlytAs will be seen the device is particularly suited for use on alternatingcurrent circuits, the part 2 being at.all times very highly heated, andready to act as the cathode, its temperature being maintained by thelocal heating source over the intervals when the current is flowing inreverse direction and during which it ceases to operate as a cathode.

I do not limit myself to any particular form of the parts making up theelectrode but prefer the form shown for the reason among others that thepart 3 protects the tube 1 from the heat of the part 2.

My invention may obviously be employed with tubes containing in someform a substance capable on decomposition of releasing a gas suitablefor being ionized and rendered luminous by the electric energy passingthrough the tube from end to end.

'What I claim as my invention is 1. In a vacuum tube lamp an electrodecomprising a cylinder or cup of conducting material and a conductorlocated within the same combined with means independent of the dischargefor heating the said conductor.

2. Ina vacuum tube, the combination of an electrode made in two parts orportions, both of which are connected to the same terminal and mayoperate both as the cathode combined with a source of alternatingcurrent and means for converting said current into currents of difierentvoltage fed respectively to the two portions of the cathode as a wholeand to one portion thereof at a lower voltage to heat the same locally.

3. In a vacuum tube, a glass stem provided with leading in wires for afilament in combination with a connecting wire Wrapped around said stemand joined to one end of said leading in wires within the tube, abisected cylinder of' conducting material clamped upon said stem and aninternal electrode supported by said cylinder.

4. In an internal electrode vacuum tube,

the combination of a glass stem supporting the base of the tube, and acup shaped electrode having a central perforation substantiallyconcentric with said stem, and electrically connected to one of theleading in wires.

5. In a vacuum tube, a compound internal electrode comprising anincandescent conductor joined to leading in wires by which itmaybe'furnished with local heating current, and a cylindrical dischargereceiving electrode having connections with one of the leading in wireswithin the tube.

6. In a vacuum tube, the combination with a working electrode thereformade in two parts or portions, one part consisting of an mcandescingconductor mounted upon the other part and a source of electric energyfor heatin said incandescing conductor locally during its operation as adischarge receiving portion of the electrode.

7. The combination with the electrode for a vacuum tube, of anincandescing conductor mounted on the same and forming a part of thedischarge receiving surface of said electrode and means for passing alocal heating currentthrough the incandescing portion, as and for thepurpose described.

8. A compound electrode for'a vacuum tube comprising a main dischargereceiving portion and a supplemental portion consisting of a conductingfilament mounted on the main portion combined with a transformer havinga secondary connected to both portions'of the electrode and means. forfurnishing alternating currents at a lower tension to the conductingfilament, as and for the purpose described.

9. In a vacuum tube, the combination with a locally heated electrode ofa transformer secondary for supplying heating current and an independentsecondary having its terminals connected respectively to the electrodesby which current is passed through the contained gas or vapor.

10. A vacuum tube provided with a conductor at each end operating as anelectrode, each conductor having its endsconnected to a source ofalternating current independent of that supplying the other, a thirdsource of alternating current connected to one of each of saidconductors.

DANIEL MCFARLAN MOORE.

Witnesses:

C. T. TISOHNER, J r., EDWARD COLE.

